Place salmon fillet on a piece of wax paper. Make a paste using the liquid smoke, sugar and salt. Spread mixture on both sides of the salmon fillet using your hands.. Wrap the fillet in the wax paper and then place in a plastic bag and tie securely. Place this is a deep dish and place in the refrigerator. Turn the bag once daily for 8 days. You will see the oil coming from the fish. When ready to serve, remove the wax paper and using a very sharp, long blade knife, slice on a 45 degree angle into thin slices.